1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
|
This patch updated for the 5.4.199 kernel on Friday, 24 June 2022 by
John Klug <john.klug@multitech.com>
From d5ebaa7c5f6f688959e8d40840b2249ede63b8ed Mon Sep 17 00:00:00 2001
From: Soenke Huster <soenke.huster@eknoes.de>
Date: Sun, 23 Jan 2022 15:06:24 +0100
Subject: Bluetooth: hci_event: Ignore multiple conn complete events
When one of the three connection complete events is received multiple
times for the same handle, the device is registered multiple times which
leads to memory corruptions. Therefore, consequent events for a single
connection are ignored.
The conn->state can hold different values, therefore HCI_CONN_HANDLE_UNSET
is introduced to identify new connections. To make sure the events do not
contain this or another invalid handle HCI_CONN_HANDLE_MAX and checks
are introduced.
Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=215497
Signed-off-by: Soenke Huster <soenke.huster@eknoes.de>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
---
include/net/bluetooth/hci_core.h | 3 ++
net/bluetooth/hci_conn.c | 1 +
net/bluetooth/hci_event.c | 63 ++++++++++++++++++++++++++++++----------
3 files changed, 52 insertions(+), 15 deletions(-)
diff -Naru a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
--- a/include/net/bluetooth/hci_core.h 2022-06-24 09:07:33.521766338 -0500
+++ b/include/net/bluetooth/hci_core.h 2022-06-24 09:16:20.317754010 -0500
@@ -193,6 +193,9 @@
#define HCI_MAX_SHORT_NAME_LENGTH 10
+#define HCI_CONN_HANDLE_UNSET 0xffff
+#define HCI_CONN_HANDLE_MAX 0x0eff
+
/* Min encryption key size to match with SMP */
#define HCI_MIN_ENC_KEY_SIZE 7
diff -Naru a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
--- a/net/bluetooth/hci_conn.c 2022-06-24 09:08:47.105764616 -0500
+++ b/net/bluetooth/hci_conn.c 2022-06-24 09:16:20.317754010 -0500
@@ -504,6 +504,7 @@
bacpy(&conn->dst, dst);
bacpy(&conn->src, &hdev->bdaddr);
+ conn->handle = HCI_CONN_HANDLE_UNSET;
conn->hdev = hdev;
conn->type = type;
conn->role = role;
diff -Naru a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
--- a/net/bluetooth/hci_event.c 2022-06-24 09:09:10.825764061 -0500
+++ b/net/bluetooth/hci_event.c 2022-06-24 09:19:52.017749056 -0500
@@ -2494,6 +2494,11 @@
struct hci_ev_conn_complete *ev = (void *) skb->data;
struct hci_conn *conn;
+ if (__le16_to_cpu(ev->handle) > HCI_CONN_HANDLE_MAX) {
+ BT_DBG("Ignoring HCI_Connection_Complete for invalid handle");
+ return;
+ }
+
BT_DBG("%s", hdev->name);
hci_dev_lock(hdev);
@@ -2510,6 +2515,17 @@
conn->type = SCO_LINK;
}
+ /* The HCI_Connection_Complete event is only sent once per connection.
+ * Processing it more than once per connection can corrupt kernel memory.
+ *
+ * As the connection handle is set here for the first time, it indicates
+ * whether the connection is already set up.
+ */
+ if (conn->handle != HCI_CONN_HANDLE_UNSET) {
+ BT_DBG("Ignoring HCI_Connection_Complete for existing connection");
+ goto unlock;
+ }
+
if (!ev->status) {
conn->handle = __le16_to_cpu(ev->handle);
@@ -4177,6 +4193,11 @@
struct hci_ev_sync_conn_complete *ev = (void *) skb->data;
struct hci_conn *conn;
+ if (__le16_to_cpu(ev->handle) > HCI_CONN_HANDLE_MAX) {
+ BT_DBG("Ignoring HCI_Sync_Conn_Complete event for invalid handle");
+ return;
+ }
+
BT_DBG("%s status 0x%2.2x", hdev->name, ev->status);
hci_dev_lock(hdev);
@@ -4200,23 +4221,19 @@
goto unlock;
}
+ /* The HCI_Synchronous_Connection_Complete event is only sent once per connection.
+ * Processing it more than once per connection can corrupt kernel memory.
+ *
+ * As the connection handle is set here for the first time, it indicates
+ * whether the connection is already set up.
+ */
+ if (conn->handle != HCI_CONN_HANDLE_UNSET) {
+ BT_DBG("Ignoring HCI_Sync_Conn_Complete event for existing connection");
+ goto unlock;
+ }
+
switch (ev->status) {
case 0x00:
- /* The synchronous connection complete event should only be
- * sent once per new connection. Receiving a successful
- * complete event when the connection status is already
- * BT_CONNECTED means that the device is misbehaving and sent
- * multiple complete event packets for the same new connection.
- *
- * Registering the device more than once can corrupt kernel
- * memory, hence upon detecting this invalid event, we report
- * an error and ignore the packet.
- */
- if (conn->state == BT_CONNECTED) {
- bt_dev_err(hdev, "Ignoring connect complete event for existing connection");
- goto unlock;
- }
-
conn->handle = __le16_to_cpu(ev->handle);
conn->state = BT_CONNECTED;
conn->type = ev->link_type;
@@ -4985,6 +5002,11 @@
struct smp_irk *irk;
u8 addr_type;
+ if (handle > HCI_CONN_HANDLE_MAX) {
+ BT_DBG("Ignoring HCI_LE_Connection_Complete for invalid handle");
+ return;
+ }
+
hci_dev_lock(hdev);
/* All controllers implicitly stop advertising in the event of a
@@ -5026,6 +5048,17 @@
cancel_delayed_work(&conn->le_conn_timeout);
}
+ /* The HCI_LE_Connection_Complete event is only sent once per connection.
+ * Processing it more than once per connection can corrupt kernel memory.
+ *
+ * As the connection handle is set here for the first time, it indicates
+ * whether the connection is already set up.
+ */
+ if (conn->handle != HCI_CONN_HANDLE_UNSET) {
+ BT_DBG("Ignoring HCI_Connection_Complete for existing connection");
+ goto unlock;
+ }
+
le_conn_update_addr(conn, bdaddr, bdaddr_type, local_rpa);
/* Lookup the identity address from the stored connection
|
